For human life, oxygen is the most important element/gas. Most of the body metabolic energy is created by oxygen. Human body is adapted to extract oxygen from air by way of breathing. After breathing air, the lungs extract oxygen which is supplied to all parts of the body. Each and every cell in the body requires oxygen to function, repair, and restore by them self.
Nowadays, due to increase on air pollution, the air is polluted with harmful gases and dust. People may not know by themselves that a sufficient level of oxygen in the environment is present or not. Moreover, in closed areas like shopping malls and underground tunnels, there is a high risk of low oxygen level and may contain a high level of toxic gases in air. Due to lack of oxygen from environment, the body suffers with various health issues like suffocation, head ache, fatigue. At times it may leads to life threatening situation. The low existence of oxygen level cannot be detected by humans just by breathing the air. Many places like Malls, Theatres, temples, high altitude mountains exist, where people gather in bulk, resulting into marginal reduction in the oxygen level in a short span of time, without the knowledge of the people. For example, oxygen level may vary inside a closed room where more than four members are sleeping in the closed room, places like airport, railway station, etc.
There are systems and devices available in the art which teach towards detecting of harmful gases and low oxygen level. However, these systems can only alert the user of the health hazardous situation.